1. Field of the Invention
The invention relates to multicomponent cartridges for proportioning and dispensing at least two different plastic materials such as, two-component adhesives or sealants in which the components are stored separately from one another before use and are mixed with one another only for use.
2. Description of the Related Art
The invention relates in particular, to a multichamber cartridge made from injection-molded plastic for proportioning and dispensing two or more component plastic materials, with at least two cartridge tube wall parts located one inside the other to form at least two chambers that receive one material component each, an end wall part located at the anterior end of the cartridge tube wall parts on which a mouthpiece for dispensing the plastic material components from the cartridge is formed, and with piston elements inserted in the rear end of the cartridge tube wall parts to express the material components.
Such two-chamber cartridges for two-component materials with cartridge tube wall parts located coaxially within one another are already known; see for example U.S. Pat. 2,826,339 (Maillard), U.S. Pat. No. 4,366,919 (Anderson), and U.S. Pat. No. 4,846,373 (penn et al). In the known two-chamber cartridges, the tube wall parts and the end wall part are produced integrally with one another in one injection-molding process from plastic requiring a correspondingly complicated and expensive injectionmolding tool.
The known two-chamber cartridges according to U.S. Pat. No. 2,826,339 and U.S. Pat. No. 4,846,373 are also provided with shutoff valves at the outlet, which are designed to prevent the material from continuing to flow when the pressure on the piston elements is released. In U.S. Pat. No. 2,826,339, these shutoff valves are designed as check valves and are mounted separately in the outlet channel of each chamber. The shutoff valve described in U.S. Pat. No. 4,846,373 has a rotatable valve plug located crosswise in a projecting neck on the cartridge end wall, with two parallel cross bores, said bores being brought into and out of alignment with the two outlet channels of the two chambers by rotating the valve plug.